The E-isomers of 2-, 3- and 4-fluorostilbene and 4,4’-difluorostilbene and also the Z-isomers of 4-fluorostilbene have been examined as comonomers in the radical polymerization of styrene at 60-degrees-C. The low levels of incorporation of the fluoro-compounds have been measured by consideration of the 19F-NMR spectra of the copolymers, using fluorobenzene as an internal standard. The reactivities of the various fluorostilbenes towards the polystyrene radical are discussed and compared with those towards the benzoyloxy radical.